1. Field
The present invention relates generally to telecommunications systems, and more specifically to a method and system for improving battery life in mobile stations designed to receive broadcast messages.
2. Background
In cellular telephone systems such as the IS-95 family of code division multiple access (CDMA) systems defined in the IS-95, IS-95A, and IS-95B standards and earlier versions of cdma2000, a base station uses a paging channel (F-PCH) to transmit broadcast pages and broadcast messages to target mobile stations. The base station may also send broadcast indicators on quick paging channel (F-QPCH) slots to inform the target mobile stations to monitor the F-PCH channel slots for the upcoming broadcast pages and/or broadcast messages.
In the newer versions of cdma2000, the base station uses a common control channel (F-CCCH) to transmit broadcast pages, a broadcast control channel (F-BCCH) to transmit broadcast messages. The base station may also send broadcast indicators on the F-QPCH channel slots to inform the target mobile stations to monitor the F-CCCH slots for the broadcast pages, which may point to the assigned F-BCCH channel slots that carry broadcast messages.
A service provider may choose to adopt either of the above broadcasting channel protocols to broadcast messages to target mobile stations, but only the mobile stations that are designed for a chosen broadcasting channel protocol would be able to receive the broadcast messages. It is highly desirable to transmit broadcast messages using both broadcasting channel protocols such that the mobile stations that are designed to receive broadcast messages transmitted in either broadcasting channel protocol would be able to receive the broadcast messages.
Currently, if a service provider transmits a broadcast message using both broadcasting channel protocols, the broadcast indicators on the F-QPCH channel slots, which may be used to signal a group of mobile stations to monitor the broadcast pages on either the F-PCH or F-CCCH channel, may cause false signaling to other mobile stations. For example, a broadcast indicator on a F-QPCH channel slot that correctly points to a broadcast page slot on the F-PCH channel may also erroneously point to a broadcast page slot on the F-CCCH channel. Consequently, the mobile stations that are designed to monitor the F-CCCH channel slots may be unnecessarily awakened to monitor the F-CCCH channel slots. Therefore, these mobile stations may suffer from unnecessary battery consumption.
There is a need in the art for providing broadcast messages using more than one broadcasting channel protocol such that the mobile stations designed to receive broadcast messages using one broadcasting channel protocol produce no false signaling to the mobile stations designed to receive broadcast messages using other broadcast channel protocols.
One aspect of the present invention is directed to a method and system for providing broadcast messages using more than one broadcast channel protocol. The method and system may include transmitting a plurality of first broadcast page slots on a first channel, transmitting a plurality of second broadcast page slots on a second channel, and transmitting a plurality of broadcast indicators on a third channel, such that each one of the plurality of broadcast indicators may point to only one of the first or second broadcast page slots.
In one embodiment of the present invention, the first broadcast page slots on the first channel may be shifted with respect to the second broadcast page slots on the second channel.
In another embodiment of the present invention, the first broadcast page slots on the first channel and the second broadcast page slots on the second channel may be transmitted at different broadcast page cycles.
Another embodiment of the present invention is directed to a base station for providing broadcast messages, which may include a transmitter and a processor. The transmitter may be adapted to transmit a plurality of first broadcast page slots on a first channel, transmit a plurality of second broadcast page slots on a second channel, and transmit a plurality of broadcast indicators on a third channel. The processor may be adapted to control the transmitter such that each one of the plurality of broadcast indicators points to only one of the first or second broadcast page slots.
In one embodiment of the present invention, the processor may be further adapted to shift the plurality of first broadcast page slots on the first channel with respect to the plurality of second broadcast page slots on the second channel.
In one embodiment of the present invention, the processor may be further adapted to control the transmitter to transmit the plurality of first broadcast page slots on the first channel and the plurality of second broadcast page slots on the second channel at different broadcast page cycles.